Incubators for infants, especially for newborn and premature babies (neonates), are generally known. They play an important role above all in the area of intensive care, for example, in supporting the developmental and growth processes of newborn babies. It is usually ensured by means of such incubators that the infant to be treated is exposed to controlled environmental conditions. Incubators according to the present invention are also called thermotherapy devices. Both closed and open devices are known in this connection. Closed devices are usually characterized by the presence of a pivotable or openable covering hood. Such a covering hood is, as a rule, missing in open devices. An existing covering hood can be removed or opened in so-called hybrid devices, so that one and the same device can be operated in both the open care mode and the closed care mode. Regulation of the temperature that prevails in the incubator is especially important in any case. Incubators for infants are therefore usually heated.
The heating of such incubators especially in the closed care mode may be carried out, for example, by means of a convective heater. The incubator or the heater of the incubator usually has a fan impeller for this, which brings about circulation of the air in the interior space. The circulated air in the interior space will then flow over a heat exchanger element before it enters the area in which the infant to be treated is located. Typical heat exchanger elements (heat transfer elements) of such a heater may be, for example, heating coil tubes or rib-like heating elements. However, heating coil tubes, in particular, have not turned out to be optimal by all means in respect to heat transfer, arrangement in the flow duct and cleaning. Attempts have therefore been made to develop different heaters for incubators.
For example, U.S. Pat. No. 6,428,465 provides for an incubator with a heater, in which heater an upper housing part and a lower housing part form a flow duct (flow chamber). This flow duct comprises an upper air chamber and a lower air chamber. The fan impeller is arranged centrally in the heater of the incubator. The air is admitted into the flow duct through air inlet areas, which are located on the front sides of the incubator. The air leaves through air outlet ducts, which are located on the long sides of the incubator. On the whole, an air inlet area is formed in this manner in the lower air chamber, and the air flows in this air inlet area towards the fan impeller, and an air outlet area arranged at right angles thereto is formed in the upper air chamber, in which air outlet area the air flows away from the fan impeller. The fan impeller is arranged at the transition between the lower air chamber and the upper air chamber such that it exerts a drawing-in action on the air stream in the lower air chamber during the operation of the incubator and a blowing-away action on the air stream in the upper air chamber arranged at right angles thereto.
A heat exchanger element, which is provided with a plurality of lamellae, is provided for heating the air stream in U.S. Pat. No. 6,428,465. These lamellae are used to enlarge the heat exchange surface and to increase the flow guiding and extend from the top side of the heat exchanger element more or less vertically upward. The heat exchanger element is arranged in the lower air chamber, i.e., in the air inlet area, in which the inflowing air flows to the fan impeller. The air outlet area is not heated.
U.S. Pat. No. 5,935,055 likewise provides for an improved heater for an incubator with a centrally arranged fan impeller. The air flowing from the incubator chamber into the flow area of the heater flows from the front sides to this central fan impeller and is heated there by means of a likewise central, ring-shaped heat exchanger element. The air is subsequently discharged back into the incubator chamber on the two long sides of the incubator.
It is problematic in both cases that the heater may be able to be cleaned in a very complicated and cumbersome manner due to the relatively complicated geometry of the respective heat exchanger elements, for example, in the area of the lamellae. In particular, there may be areas in the heater which are accessible for complete and proper cleaning with difficulty only.
In addition, it may be necessary to operate the particular heater, especially the particular heat exchanger element, with a relatively high surface temperature in order to guarantee sufficient and uniform heating of the air. The surface temperature may thus, for example, easily and markedly exceed the value of 100° C. This also applies especially to heating coils, which may have a relatively small surface.
Another problem may be represented by the elements inserted into the flow path, for example, the lamellae or the central, ring-shaped heater, from an acoustic point of view. Considerable noise may be generated by these elements.